JP6021984B2 - Chuck that can be coupled by an automated method - Google Patents

Description

  The present invention relates to a chuck according to claim 1 for gripping a workpiece or a tool with a gripping force F in a gripping space, and a system according to claim 8 comprising the chuck and a drive motor.

  In tool technology, particularly turning and milling, chucks are used to hold various workpieces or tools in the gripping space, which is formed by the jaws of the chuck. The tools may be milling heads or drills, for example, which are stored in the magazine and are automated from each magazine, for example so that various process steps can be performed on the same component. It is taken out by operation and is gripped by the chuck in a computer-controlled manner.

  Especially in chucks that are not driven by hydraulic or pneumatic pressure, for example if the chuck is no longer working with the required accuracy and if the dimensions of the chuck are not suitable for use, It needs to be replaced. In the chuck, the tool or machine component or workpiece to be machined is gripped in the gripping space formed by the face of the chuck jaws in the center of the lathe chuck.

  For example, hydraulic chucks and pneumatic chucks have the advantage that they can be switched automatically and quickly. The chuck jaws have a relatively small chuck travel, which can be realized with hydraulic and pneumatic chucks, for example only +/− 10 mm, and therefore the minimum diameter and maximum of the gripping space representing the range of variation of these chucks. The diameter is limited. In any case, the chuck can accommodate a large tool or workpiece by changing the chuck jaw arrangement or replacing the chuck jaws.

  For these reasons, the gripping force that can be achieved with these chucks is very strong. Thus, in order to be able to accommodate tools or workpieces of various dimensions, especially various diameters, the chuck must be replaced or the chuck jaws must be displaced.

  The chuck is, for example, a head chuck, a drill chuck, a lathe chuck, or a shrink fit chuck.

  In addition, chuck replacement is generally done manually, with an expert stopping the machine tool and opening the machine, opening the chuck jaws and removing the workpiece, and then replacing the chuck with a new chuck.

  The object of the present invention is therefore to provide a chuck that can be used more efficiently, in particular a chuck that reaches a high gripping force, has a wide chuck travel and at the same time is as compact as possible.

  The technical problem underlying the present invention is solved by the features of claims 1 and 8. Advantageous developments of the invention are described in the dependent claims. Combinations of any at least two of the features described in the specification, claims, and / or drawings are also included within the scope of the invention. Also, within a given value range, values within the indicated limits will be considered disclosed as boundary values and will be claimed in any combination.

  The invention is based in particular on the idea of designing a chuck by eliminating dynamometer means and / or displacement measuring means and / or other electrical components for determining the condition of the chuck, whereby The chuck can be replaced in an automated manner, or the chuck is used only to transmit drive torque from the drive motor to the chuck jaws. Another design approach that is intended to be an alternative or to be added to it is to move the movement from the largest dimension of the gripping space to the smallest dimension of the gripping space to the gear train and the gear train located inside the chuck. With a drive motor that can be coupled, this can be done automatically only by the drive motor and the movement of the chuck jaws performed by the drive motor through the gear train. Therefore, this chuck can be used more flexibly for a larger number of workpieces.

  In particular, the gear train, in particular the spiral ring, between the drive motor and the chuck jaw drive that drives the chuck jaws directly, is created purely mechanically and / or purely positive. Is specified. Further, in order to accurately adjust the plurality of chuck jaws or each chuck jaw, a hydraulic drive unit or a pneumatic drive unit may be further provided in the chuck jaw drive unit. This additional drive is particularly advantageous for fine positioning of the chuck jaw travel, while the gear train with the chuck jaw drive is a relatively large travel of at least 1 cm, in particular at least 2 cm, preferably at least 5 cm. It is for positioning.

  The gripping space is defined by the number of chuck jaws, and this gripping space is used to accommodate workpieces and / or tools of various contours in the tool / workpiece gripping section. In general, the gripping section is provided as a cylindrical section in which one gripping end of the workpiece / tool is polygonal. The chuck jaws grip the tool / workpiece by pressing the jacket surface of the gripping section from at least two, generally three or four, on the jacket surface side with the gripping force F supplied by the drive motor. As a result, an adhesion action occurs between the chuck and the tool / workpiece.

  As defined in the present invention, as claimed, the chuck jaws, in particular, the drive portion provided integrally with each chuck jaw, in particular, the guide groove, the minimum position from the maximum position of the chuck jaw of each chuck. This means that the chuck jaw can be moved in translation along the gripping surface E, and therefore, the chuck jaw transfer that is necessary, for example, with a chuck jaw movable by hydraulic pressure or air pressure can be omitted. Thus, the chuck jaws can be moved without being transferred over the entire chuck travel formed by the chuck jaws of the respective chuck.

  By eliminating the functional parts that have been included in the chuck so far, not only the cost of the chuck is reduced, but also the operation of the chuck, specifically the workpiece or tool is accurately gripped and fixed, The operation of ensuring that the chuck is not displaced and / or rotated can also be reduced to essential.

  The invention is particularly suitable for lathe chucks or milling chucks.

  According to an embodiment of the present invention, it is particularly advantageous if the chuck is made purely mechanically, partly because the manufacture of the chuck is simplified and the reliability of the chuck is increased. It is.

  Gripping a workpiece or tool by adjusting the opening width D between the at least two chuck jaws and / or by directly adjusting the gripping force F by a drive motor, in particular made as a servomotor The chuck control / adjustment in this case is performed directly by the drive motor, eliminating the need for additional sensors or measuring means. The drive motor may in particular be of torque control and / or position control and requires calibration for each chuck in the servo motor and the closed control loop of the servo motor. In this way, a particularly simple, efficient and very accurate control / adjustment of the chuck is possible.

  According to an advantageous embodiment of the invention, it is provided that there is a gripping space on the front side of the chuck and a coupling means on the back side facing away from the front side of the chuck. This configuration facilitates replacement and use of the chuck and enables a structure that saves space.

  This coupling means comprises a drive shaft, particularly elastically mounted, acting positively and comprising a coupling element arranged on the back, in particular an internal tooth system provided on the drive side of the drive shaft, Coupling is possible by placing a chuck on the corresponding coupling element in that it has a drive shaft and this internal gear system positively engages the corresponding coupling element of the drive motor shaft.

  According to another advantageous embodiment of the invention, this coupling means comprises at least one, preferably one, mechanical alignment means for automatic alignment when coupling the chuck to the drive motor. In particular, it is defined that the peripheral edge has a closed and / or in the form of an approach bevel surrounding a ring-shaped drive shaft. The reliability of the bonding process is increased and the bonding elements as well as the corresponding bonding elements are protected by this means.

  By elastically attaching the drive motor shaft, even when the coupling element is displaced with respect to the corresponding coupling element, the deviation between the coupling element and the corresponding coupling element is reduced after the start of the drive motor. The coupling can be effected by releasing it by movement and engaging the corresponding coupling element with the coupling element by means of a spring force.

  As claimed in the present invention, according to one embodiment, the gear train further defines that it has at least two shafts, one on the drive side and the other on the output side. Furthermore, it may be advantageous to align the at least two axes to have one direction of rotation, the directions being different, in particular orthogonal. According to another embodiment of the invention, at least one of the shafts, in particular the drive shaft, extends parallel to one longitudinal axis L of the chuck, in particular coincident with the longitudinal axis L.

  Other advantages, features, and details of the present invention will be apparent from the following description of exemplary preferred embodiments and drawings.

It is sectional drawing of the chuck | zipper and chuck | zipper receiving part in 1st Embodiment as claimed in this invention. It is sectional drawing of the chuck | zipper and chuck | zipper receiving part in 2nd Embodiment claimed by this invention.

  In the drawings, the same reference numerals are assigned to the same components or components having the same action.

  The upper side of FIG. 1 shows the chuck 1 housed in a chuck receiving part 13, which is shown on the lower side for coupling the chuck 1 to a drive motor 20 connected to a shaft.

  The chuck 1 has a plurality of chuck jaws 2 on a front surface 1v thereof, and these chuck jaws 2 can be moved linearly or translated along the gripping surface E by a spiral ring 3 positioned therebelow. . The spiral ring 3 engages with the corresponding guide groove 2f of the chuck jaw at the spiral portion 3s located on the surface 3o. The chuck jaw 2 is guided in the linear direction by the linear guide 4.

  At the bottom 3u of the spiral ring 3, a crown system 3k extends over the entire periphery. The crown system 3k of the spiral ring 3 is a component of a purely mechanical gear train for transmitting the drive torque of the drive motor 20 to the chuck jaw 2, and this drive motor 20 is coupled to the gear train. be able to. Furthermore, the component of this gear train is a spline shaft 5 that acts as an output shaft, which spline shaft 5 engages with the crown system 3 k of the spiral ring 3 and rotates the spiral ring 3. The chuck jaw 2 is translated in a uniform manner by the rotation of the spiral ring 3.

  The spline shaft 5 has a bevel gear 7 on the drive side, and the spline shaft 5 is attached to a ball bearing 6, which forms an ideal attachment form. Simpler versions exist as bearings or friction bearings. The rotational axis R of the spline shaft 5 is parallel to the gripping surface E, and the rotational driving motion is 1 of the chuck 1 via another bevel gear 9 of the drive shaft 8 engaged with the bevel gear 7 of the spline shaft 5. In this embodiment, this axis L is orthogonal to the rotation axis R or the gripping surface E, and is positioned at the center of the chuck 1. In this embodiment, this position is the center of the gripping space 21. Matches Z. The rotational axis of the drive shaft 8 coincides with the longitudinal axis L.

  On the other hand, a ball is attached to the drive shaft 8, and the drive side thereof has an internal tooth system 11, and the internal tooth system 11 is provided in a hole 12 disposed inside the chuck 1.

  The drive side of the drive shaft 8 terminates in a recess 24, which is at least partially positioned for automatic alignment when the chuck 1 is coupled to the drive motor 20 or the chuck receiver 13. 22 is used. For this purpose, there is a ring-shaped approach slope part 23 surrounding the drive shaft 8, and this approach slope part 23 and a ring-shaped approach slope part 25 in the corresponding convex part 26 (tongue-in-groove connection). It serves as an alignment means 22 when coupled in the form of

  The coupling part 10 between the chuck 1 and the drive motor 20 or the chuck receiving part 13 has an internal tooth system 11 provided in the hole 12 and a head tooth system 16 provided in one coupling element 15. Both of these are provided on the motor shaft 14. Furthermore, the motor shaft 14 as a coupling connection has a sleeve 17 in addition to the coupling element 15 and the head tooth system 16, which has a head tooth system 16. 16 is used as the coupling element 15. In the sleeve 17, the string spring 18 is guided, and the motor shaft 14 is supported against the spring force. Maximum movement of the sleeve 17 relative to the motor shaft 14 is limited by the pin 19 guided in the slot 27.

  The motor shaft 14 is driven by a servo motor 20.

  Therefore, the servo motor 20 drives the motor shaft 14 on the one hand, drives the drive shaft 8 and the spline shaft 5 coupled thereto via the coupling portion 10, and thereby drives the spiral ring 3 and the chuck jaw 2. To do. On the other hand, the current and voltage can be continuously read via the servo motor, and therefore after the servo motor 20 is pre-calibrated with respect to the chuck 1 for the resistance applied to the chuck jaw 2 by the workpiece, the servo motor 20 The gripping force F can be controlled / adjusted via fluctuations in the output or current curve and / or voltage curve. Instead of the servomotor 20, a drive motor with mechanical / electrical feedback can also be used.

  FIG. 2 shows a vise chuck 1 ′ having two jaws 2 ′, and between the surfaces 2 s ′ of the jaws 2 ′, there is a gripping space 21 with an opening width D that can grip a workpiece. Is formed. The translation movement of the jaw 2 'along the gripping surface E is performed via the spindle 32, and as soon as the spindle 32 rotates, its output side translates one of the two chuck jaws 2'. The rotation of the spindle 32 is performed on the output side by a chain drive unit 31 coupled to the spindle 32, and the drive side of the chain drive unit 31 is driven by a shaft 33. On the other hand, the shaft 33 is driven by a bevel gear 34 in the gear 35 of the shaft 33. The bevel gear 34 is disposed on the output side of the drive shaft 8 ', and the drive side of the drive shaft 8' is created in the same manner as in the embodiment shown in FIG.

  The chuck receiving portion 13, the drive motor 20, and the coupling portion 10 are made the same as those in the first embodiment.

  Furthermore, what is common to the two embodiments shown in FIGS. 1 and 2 is that the outer shape of the chuck receiving portion 13 and the outer shape of the chuck 1 are on the same plane. When not seated, it can be recognized immediately from the outside.

  In particular, a robot arm is suitable for replacing the chuck 1.

1, 1 ′ chuck 1v, 1v ′ front surface 1r, 1r ′ back surface 2, 2 ′ chuck jaw 2s, 2s ′ surface 2f guide groove 3 spiral ring 3o top surface 3k crown system 3s spiral portion 4 linear guide 5 spline shaft 6 ball bearing 7 Bevel gear 8, 8 'Drive shaft 9 Bevel gear 10 Coupling part 11 Internal tooth system 12 Hole 13 Chuck receiving part 14 Motor shaft 15 Coupling element 16 Head tooth system 17 Sleeve 18 Spring 19 Pin 20 Servo motor 21 Holding space 22 Position Alignment means 23 Entering inclined part 24 Concave part 25 Entering inclined part 26 Convex part 27 Slot 31 Chain drive part 32 Spindle 33 Axis 34 Bevel gear 35 Gear E Holding surface F Holding force D Opening width Z Center R Rotating axis L Longitudinal axis

Claims (9)

A chuck (1) for gripping a workpiece or tool with a gripping force (F) in a gripping space (21),
At least two chuck jaws (2) capable of translational movement along one gripping surface (E) in the direction of one center Z of the gripping space (21), wherein the gripping space (21) At least two chuck jaws (2) formed by the face (2s) of the chuck jaws (2);
Drive torque of a drive motor (20), which is a purely positive gear train, wherein the gear train is coupled to the gear train by means of the gear train coupling means for moving the chuck jaws (2) To the chuck jaws (2) is arranged at least mainly in the chuck (1), and the purely positive coupling means is an automatic operation and only by the drive motor (20). The drive motor (20) can be coupled to a corresponding coupling portion, and is a movement from the maximum dimension of the gripping space (21) to the minimum dimension of the gripping space (21), and the drive motor (20 A purely positive gear train capable of performing the movement performed via the gear train from
With
The chuck (1), wherein the opening width (D) and / or the gripping force (F) between the at least two chuck jaws (2) can be directly adjusted by the drive motor (20).   2. Chuck according to claim 1, wherein the purely positive coupling means is constructed purely mechanically.   The chuck according to claim 1, wherein the drive motor is configured as a servo motor.   The chuck according to claim 3, wherein current and voltage are continuously readable through the servo motor.   The chuck according to any one of claims 1 to 4, wherein the drive motor is torque-controlled and / or position-controlled. There is a gripping space (21) on the front surface (1v) of the chuck (1),
The chuck according to any one of claims 1 to 5, wherein there is a coupling means on the back surface (1r) facing away from the front surface (1v) of the chuck (1). The coupling means comprises a drive shaft (8) that is elastically attached to the drive shaft (8) and acts positively and has a coupling element arranged on the back surface (1r). ,
The chuck according to any one of the preceding claims, wherein the coupling element positively engages a corresponding coupling element (15) of a motor shaft (14) of the drive motor (20). A chuck (1) according to any one of claims 1 to 7,
The drive motor (20) provided in the chuck receiver (13) for accommodating the chuck (1) and / or the drive motor (20);
Replacement means for replacing the chuck (1) ,
The replacement means is a robot arm that automatically replaces the chuck (1) . The system of claim 8 , wherein the motor shaft (14) is resiliently mounted.

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